Engine starting mechanism



311;, 1935., p H MAURER 2 25fi7 ENGINE STARTING MECHANISM Filed March 1, 1934 IN VE/VTOR A T ORNE Y Patented Dec. 31, 1935 ,trasu PATENT FFHQE ENGINE STAR'iIb-IG P/IEGHANHSIVE Paul H. Maurer, Elmira, N. Y, assigner to Eclipse Machine Company, Elmira, N. '55., a corporation of New York Application March 1, 1934, Serial No. 713,547

13 Claims.

This invention relates to engine starting mechanism of the type in which the cranking connection is automatically established by energization of the starting motor and is interrupted when the engine starts, and more particularly to a device for electrically controlling the cranking connection.

It is an object or" the present invention to provide a starting mechanism of the above type which is efficient and reliable in operation and simple and economical in construction.

It is another object to provide such a device in which the cranking connection is in the form of gears arranged to mesh and demesh by bodily movement transverse to their axes of rotation.

It is a further object to provide such a device in which the cranking connection is positively maintained or locked until the engine starts.

It is another object to provide such a device in which the lock is rendered eiiective magnetically by the initial heavy flow of cranking current and in which the reduction of current when the engine starts is used to break the cranking connection.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawing in which:

Fig. 1 is an end view or" a preferred embodiment of the device partly in section and partly diagrammatic showing the parts in normal or idle position.

Fig. 2 is a similar view showing the parts in cranking position; and

Fig. 3 is a side elevation partly in section showing the parts in idle position.

Referring first to Fig. 3 of the drawing, there is illustrated a starting motor I having an extended armature shaft 2 on which is freely journalled a driving member in the form of a pinion 3. The pinion 3 is connected to rotate with. the armature shaft 2 by means of a suitable yielding connection illustrated in the form of a coil spring 4 anchored at 5 to a driving head 5 fixed on the armature shaft and anchored at l to a driven head 8. The driven head 8 is connected through an overrunning clutch 9 to an extension 6 i of the pinion 3 whereby the pinion is permitted to overrun the armature shaft but is yieldably driven therefrom.

A transmission member in the form of an intermediate pinion i2 is mounted to mesh with the driving pinion 3 being free to planetate around the axis of the armature shaft. As here shown this is arranged by mounting the intermediate pinion $2 on a bearing member i3 which is suitably fixed in a bracket formed by plates M and i5 journalled on smooth extensions of the driven head 8 and pinion 3 respectively, whereby the intermediate pinion I2 can swing into and out of 5 mesh with a member such as a flywheel gear it of the engine to be started.

According to the present invention means are provided for locking the intermediate pinion 52 in driving engagement with the engine meml0 ber it during the cranking operation in order to prevent disengagement thereof when the engine passes over its compression points or as a result of a false start of the engine. As here shown this locking means is in the form of a toggle device 15 comprising an arm ii pivoted at it to any suitable fixed support and pivoted at it to a second toggle arm 2! which in turn is pivoted to an extension 22 (Fig. 3) of the bearing member !3 on the swinging bracket i i, 85. The dimensions of 0 the toggle arms ii and 25 are such that when the arms are straightened out in locking position as illustrated in Fig. 2, the intermediate pinion I2 is in full mesh with the engine gear IS. The locking position of the toggle arms is preferably 25 defined by suitable means such as shoulders 22 and 23 on the toggle arms ii and 25 respectively which are arranged to engage when the toggle is in looking position.

Means are provided for bringing the toggle 30 device into full locked position in response to the initial heavy current flow when cranking starts, and for breaking the toggle in response to the reduction in current flow when the cranking load is relieved as the engine becomes self- 35 operative. As here shown this means comprises an electromagnet 26 having a few turns of heavy wire placed in series in the starting circuit which comprises the battery 25, the starting switch 26 and the starting motor i. Electromagnet 24 is 40 preferably of the so-called iron-clad type comprising a central pole piece 2? and an outer shell 23 of magnetic material mounted on a suitable fixed pivot as indicated at 3%.

A magnetic plunger 29 is arranged to slide in 45 a suitable non-magnetic guide member in the form of a tube 35, is arranged to be attracted by the pole piece 21 when it is brought into pr imity to electromagnet 24. Plunger 29 is adjustably mounted on a rod 3?: the lower 50 end of which is provided with a cross head having a slot 33 adapted to receive an extended portion 3 3) of the toggle pivot 29. The dimensions of the rod 32 and slot 33 are such that when the toggle is placed under tension by the 55 swinging of the bracket l4, It: by the action of the starting motor 5, the plunger 29 will be means in the form of a spring 49 is provided for causing the upper end of the slot 33 to strike the toggle pivot i9 and break the toggle when the plunger 29 is released by the weakening of the electromagnet 24% when the engine starts.

In order to assist in differentiating between a false start and a true start of. the engine, a time delay is preferably provided for. preventing the immediate breaking of the toggle in response to a momentary weakening of the electromagnet 24 which might be caused by a false start of the engine. As here shown, this time delay is in the form of a dash pot provided by the plunger 29 in the tube 3|. For this purpose the pole piece 2? is arranged to close the free end of the tube 3!, and an opening 35 is provided in the tube 3! at a suitable distance below the pole piece in order to permit free movement of the plunger 29 below said opening. An adjustable bleeder in the form of a channel 36 having a restricted passage regulated by the needle valve 31 is provided for regulating the time delay, and a larger opening 38 controlled by a check valve 38 is preferably provided in order to permit rapid upward movement of the toggle and rod 32 into locking position.

Suitable means such as indicated generally at 4! are provided for adjusting the tension of the releasing spring 56, and the adjustable connection indicated at GE between the plunger 29 and rod 32 permits the regulation of the air gap 53 between the plunger 29 and the pole piece 21. The device may thus be adjusted to release at any desired strength of flux through the electromagnet such as that corresponding to the free spinning condition of the starting motor when the engine starts.

In the operation of this device, starting with the parts in the positions illustrated in Fig. 1, closure of the starting switch 26 causes energization of the starting motor l whereby the driving pinion 3 is rapidly accelerated. The intermediate pinion !2, due to its rotational inertia is moved by the torque of the driving pinion 3 into engagement with the engine gear l5, whereupon the pinion I2 is moved into full mesh with the engine gear by virtue of the driving reaction of the gearing. During this time the toggle ll; 2! is placed under tension whereby the rod 82 is raised until the plunger 29 comes within the zone of influence of electromagnet 2-5 which is at this time strongly energized by the initial heavy iiow oi cranking current as the starting motor initiates the cranking operation. The plunger 29 is thereby caused to draw the toggle ll, 2! into its looking position as illustrated in Fig. 2 where it is maintained during the cranking operation irrespective of any tendency which the engine gear It might have to overrun as the engine passes over its compression points or because of weak explosions of the engine.

When the engine starts, the relief of the cranking load on the starting motor causes the electromagnet 2G to be weakened sufiiciently to release the plunger 28 which moves slowly down ward under the action of the spring 48 as retarded by the dash pot time delay. As soon as the plunger 29 reaches the opening 35 in the tube 35 it is permitted to move freely, and the upper end of the slot 33 strikes the toggle pivot i Q breaking the toggle and permitting the bracket Hi, 15 to swing back to idle position.

During the period of the time delay, the inter= mediate pinion i2 is driven by the engine gear IE, but the overrunning clutch 9 permits the driving pinion 3 to overrun the armature shaft 2 whereby the starting motor is not driven by the engine and is therefore not accelerated above its free-running speed.

In some installations it may be preferred to omit the overunning clutch 9 and connect the driving pinion 3 directly to the driven head 8. With this arrangement, when the engine starts the motor is driven from the engine until the gearing is disconnected. If the disconnection does not take place until the motor has been accelerated above its free-spinning speed, the current flow through the motor will be reduced to a value less than the free-spinning current of the motor. The electromagnetic device may therefore be so adjusted as to release only at a lower current value than the free-spinning current. Obviously this maintains the gearing connection locked until the engine has become self-operative and accelerated considerably above cranking speed, which assures the continuity of the cranking operation until a true start has been secured.

When the electromagnetic device is adjusted to release only at amperages below free-spinning values, the dash not time delay becomes unnecessary and may be omitted.

Although but one embodiment of this invention has been shown and described in detail, it will be understood that other embodiments are possible and various changes may be made in the details and arrangements of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. Engine starting mechanism including a motor, a driving member connected thereto, a transmission member movable thereby into driving engagement with a member of an engine to be started, means for positively locking the transmission member in driving position and means responsive to the reduction in current caused by the acceleration of the starting motor when.the engine starts for releasing said locking means.

2. Engine starting mechanism including a motor, a driving member connected thereto, a transmission member movable thereby into driving engagement with a member of an engine to be started, means for positively locking the transmission member in driving position, means responsive to the heavy cranking current of the motor for rendering said locking means effective and means responsive to the reduction in current caused by the acceleration of the starting motor when the engine starts for releasing said locking means.

3. Engine starting mechanism including a motor, a driving member connected thereto, a transmission member movable thereby into driving engagement with a member of an engine to be started, means for holding the transmission member in driving position, means responsive to the heavy cranking current of the motor for rendering said holding means eilectivameans responsive to the reduction in current when the engine starts for releasing said holding mechanism and means for delaying such release for a predetermined time after such reduction in current takes place.

4. Engine starting mechanism including a motor, a driving member connected thereto, a transmission member movable thereby into driving engagement with a member of an engine to be started, means including a toggle device for holding the transmission member in driving position, means responsive to the heavy cranking current of the motor for straightening said toggle for rendering said holding means effective, and means responsive to the reduction in current when the engine starts for breaking said toggle to release the holding means.

5. Engine starting mechanism including a motor, a driving member connected thereto, a transmission member driven from said driving member and bodily movable transverse to its axis into and out of engagement with a member of an engine to be started, means including magnetic means responsive to the cranking current through said motor for locking the transmission member in engagement with the engine member and means responsive to the relief of the cranking load when the engine starts for releasing said locking means and returning the transmission member to idle position, said locking and releasing means including adjustable means whereby the releasing means may be arranged to function at a predetermined value of the cranking current.

6. Engine starting mechanism including a motor, a driving member connected thereto, a transmission member bodily movable transverse to its axis into and out of en agement with a member of an engine to be started, means including magnetic means responsive to the crank ing current through said motor for locking the transmission member in engagement with the engine member, means responsive to release of the cranking load when the engine starts for releasing said locking mean means for delaying the release of the locking means for a. predetermined time after the engine starts, and an overrunning driving connection between the driving member and the transmission member.

7. Engine starting mechanism including a motor, a driving member connected thereto, a transmission member driven from said driving member and bodily movable transverse to its axis into and out of engagement with a member of an engine to be started, means includ g a toggle device and magnetic means responsive to the cranking current throu h said motor for straightening said toggle and thus locking the transmission member in operative engagement with the engine member and means responsive to relief of the cranking load when the en he starts for breaking said toggle an returning the transll'llSlOi'l member to idle position.

8. An electrical starting sy tem or internal combustion engines including a not a driving pinion rotated thereby, an intermediate pinion driven from the driving pinion and mounted for bodily movement transverse to its axis into driving engagement with a gear on the engine to be started, yielding means biasing the intermediate pinion toward idl position, means for locking the intermediate pinion in driving position, means for tripping said locking means, magnetic means responsive to cranking current for holding the tripping means during the cranking operation ing the intermediate pinion in driving position,

means for tripping said locking means, magnetic means responsive to cranking current for holding the tripping means during the cranking operation and means for delaying the action of the tripping means for a predetermined time after the engine starts, said means being ar- H ranged so as not to interfere with the locking. action of the locking means.

10. Engine starting mechanism including a motor, a driving member constantly connected for rotation therewith, a transmission member movable thereby into driving engagement with a member of an engine to be started, and means including electromagnetic means responsive to current traversing the starting motor for positively locking the transmission member in driving position until said cranking current is reduced to a value less than the free-spinning current of the motor.

11. Engine starting mechanism including a motor, a driving member constantly connected for rotation therewith, a transmission member movable thereby into driving engagement with a member of the engine to be started, means including electromagnetic means energized by current traversing the starting motor for positively locking the transmission member in operative engagement with the engine member, said locking means including elements adjustable to release the tansmission member in response to a reduction of curr nt flow through said motor to a predetermined value below the value of the free-spinning current thereof.

12. Engine starting mechanism including a motor, a driving member constantly connected for rotation thereby, a transmission member movable thereby into driving engagement with a member of the engine to be started, means for positively locking said transmission member in operative position, and means responsive to a predetermined acceleration of the starting motor for releasing said locking means.

13. Engine starting mechanism including a motor, a driving member constantly connected for rotation thereby, a transmission member movable thereby into driving engagement with a member of the engine to be started, means for positively locking said transmission member in operative position irrespective of the driving reaction between the and means responsive to a predetermined acceleration of the starting motor by the engine member when the engine starts for releasing said locking means.

PAUL H. MAURER. 

